Phidippus johnsoni – Red-Backed Jumping Spider
Edited to add (7/11/11): Thanks to a couple of knowledgeable and generous commenters (below) the positive ID on this jumping spider is “Ms.” 
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I found this little Mr. (or Ms.) on the kitchen ceiling a few days ago. Before I could grab my telephoto to see precisely what type of venomous spider might be parachuting onto my head during dinner, he (or she) disappeared.
Today, I saw the black splotch in my peripheral vision again. But I couldn’t get much of a shot in the available light without my tripod (which I routinely forget in the car).
Blur of Red-Backed Jumping Spider - Phidippus johnsoni - ©ingrid
I could obviously make out the red stripes on the spider’s back. But I don’t know enough about spiders to make a firm ID. Google turned up references to the most dangerous spider in Australia, the Redback . . . a species I could have dismissed had there not been one alleged sighting in Texas.
So, I figured that absent any species consensus, I’d have to find a way to get the guy with the redback (but not necessarily a Redback) outside without risking interaction. Spiders get the benefit of the doubt in this household.
When he climbed on a painting, I seized the moment. I grabbed the frame and swung it outside the door, just as my spider friend plummeted outdoors on a sheen of silk.
The anthropomorphic interpretation of this spider’s expression: “What in the hell was that about?”
I positively identified this guy after the fact. Had I known my California Arachnidae, I’d have known he (or she) was a Red-Backed Jumping Spider (Phidippus johnsoni), common in California. And I might have known the preferred habitat is tucked under something on the ground, not on a leaf — where he landed.
I would have understood that although it has some venom, its bite is not fatal. An encounter would generally only happen if the spider felt threatened, and then, a spider-inflicted injury would render minor swelling and pain. (Being catapulted out the door on the frame of a painting probably constitutes being “threatened.” So if I’d been bitten, whose fault would that have been?)
A person who raises Red-Backed Jumping spiders commented on my Flickr photo, attesting to their relatively docile nature. (Lots more great Red-Backed Spider pics at their Flickr site: The Green Thumb/Spider Pics.)
Here was my last vision of the eight-legged, dancing upon its gossamer silks before trundling off down the tree limb.
Gossamer (silk) of the Red-Backed Jumping Spider - ©ingrid
{ 13 comments… read them below or add one }
If it has a black stripe in the center of the red, it’s a female. If it’s just red, it’s a male. I found one at school (at first I thought it was a ladybug) and just had to figure out what it was. (;
so it’s a Ms.
My son is recovering from a spider bite, allegedly from a ‘latrodectus mactans’ (black widow). So I am on the lookout for squishing anything with eight legs, black, and moves in our house. I got one this morning with a combination of three spray cans of black flag and a swatter. What was left of him stuck in the swatter seems to indicate that he was innocent an possibly really a kind of ally. Sorry nature, but better to be safe than sorrry here in the southern California desert, home to black widows the size of silver dollars and birds of prey the size of buicks.
O yes, He is a she and was a red backed jumper, sorry Ms.
I live in southern Louisiana . I found a back jumper spider . Is this a spider common in Louisiana?
Barry, you can find jumping spiders around the world, and — I had to look it up to make sure — definitely in Louisiana. But I’m not sure which type of jumping spider you’d see there.
@ Kat & C.D., thanks and sorry for the delayed acknowledgement.
It a Phidippus Johnson
Hi, Barry, thanks for the clarification. I don’t know for sure and everything I’ve read so far claims the range for Phidippus johnsoni is “western North America from the Rocky Mountains to the Pacific Coast.” I’ll see if I can find out, or perhaps someone with a bit more information on this species will happen upon the post.
Thank you I still look up more on this spider too.
Barry, I found this in Bug Guide, a Phidippus whitmani photographed in St. Landry Parish, Louisiana. The link: http://bugguide.net/node/view/161494/bgpage. The website might have additional information pertinent to your quest.
How can email you a photo of the spider
Barry, just send to ingrid@thefreequark.com
I email you a photo of it.